Astronomy
esiegel | October 15, 2010"The chess-board is the world, the pieces are the phenomena of the universe, the rules of the game are what we call the laws of Nature. The player on the other side is hidden from us." -T. H. Huxley
There's an amazing interactive application on the Scale of the Universe that was just pointed out to me (thanks, Brian L.), and I had to share! So go play with it (again, link here), and let's talk about it.
You are here, of course. A human being is somewhere between 1 and 10 meters, to be rough. Being able to zoom from scales as small as the Planck Scale (~10-35 meters) all the way up to the…
esiegel | October 14, 2010Calvin: Why does the sky turn red as the sun sets?
Calvin's Dad: That's all the oxygen in the atmosphere catching fire.
Calvin: Where does the sun go when it sets?
Calvin's Dad: The sun sets in the west. In Arizona actually, near Flagstaff. That's why the rocks there are so red.
Calvin: Don't the people get burned up?
Calvin's Dad: No, the sun goes out as it sets. That's why it's dark at night.
Calvin: Doesn't the sun crush the whole state as it lands?
Calvin's Dad: Ha ha, of course not. Hold a quarter up. See, the sun's just about the same size.
Calvin: I thought I read that the sun was…
drorzel | October 12, 2010SteelyKid is a big fan of the classic children's book Goodnight Moon, which, if you haven't spent the last sixty-odd years in a cave, you probably know features a bunny saying goodnight to a variety of objects in a great, green room. The attentive toddler will find a lot to look at in the pictures-- there's a mouse in every one that SteelyKid delights in pointing out-- but an inquiring adult might well ask "Just how long does it take this bunny to say goodnight to all this stuff, anyway?"
Well, we can answer this question with SCIENCE! You see, there are six pictures in the book showing the…
esiegel | October 11, 2010"I was like a boy playing on the sea-shore, and diverting myself now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me." -Isaac Newton
"Either you decide to stay in the shallow end of the pool or you go out in the ocean." -Christopher Reeve
Today is Columbus Day here in the United States. And unlike pretty much everyone else I know, I've been looking forward to Columbus Day for weeks, now.
Why's that?
After all, it's not like I get off from work, or that I think Columbus was some idealized version of a human…
cevans | October 11, 2010
The author, dishing.
To get to the National Radio Telescope Observatory, you have to be committed.
Well, first, you have to be in New Mexico -- about an hour's drive south of Albuquerque, in the plains of San Augustin, to be precise, a Pleistocene lakebed bordered by the northern end of the Chihuahuan Desert and dotted with arid shrubs. Despite being some 6,970 feet above sea level, it feels like the basement of the world, wide and flat and under the massive Southwestern sky. Driving to the Observatory, the home of the famous "Very Large Array" of radio telescopes, is an exercise in…
esiegel | October 8, 2010"You can't have a light without a dark to stick it in." -Arlo Guthrie
You know the story. Every galaxy we look out at, with hardly any exceptions, appears to be moving away from us. Not only that, but the farther away a galaxy appears to be, the faster it appears to move away from us!
What do we observe that leads us to believe this? Well, thanks to Edwin Hubble, who looked at the spectra of distant galaxies, we discovered that, compared to Earth, where we make atoms emit and absorb light at very specific wavelengths (or frequencies):
for distant galaxies, these emission/absorption lines…
esiegel | October 7, 2010"Imperfection clings to a person, and if they wait till they are brushed off entirely, they would spin for ever on their axis, advancing nowhere." -Thomas Carlyle
When you take a look up at the sky, the two most prominent objects are the Sun and the Moon.
And every day, like clockwork, they rise in the East and set in the West.
Why's that?
Because the Earth rotates on its North-South axis! Not only does it rotate, but it rotates from West to East, and that's why we see everything rise in the East and set in the West over the course of a day or night.
Image Credit: Phil Hart.
It gets…
esiegel | September 29, 2010"Goldilocks was hungry. She tasted the porridge from the first bowl.
'This porridge is too hot!' she exclaimed.
So, she tasted the porridge from the second bowl.
'This porridge is too cold,' she said.
So, she tasted the last bowl of porridge.
'Ahhh, this porridge is just right,' she said happily and she ate it all up." -Goldilocks and the Three Bears
Life as we know it on Earth all makes great use of one particular molecule in one particular phase:
Liquid water! Having a liquid phase to water requires an atmosphere with enough pressure (and something with even 1% of Earth's atmosphere will…
krandall | September 28, 2010By Dr. Paul EstradaPlanetary physicist at the Carl Sagan Center for the Study of Life in the Universe, SETI Institute, and Gail Jacobs
If planets are a dime a dozen, moons are less than a penny each. There are at least 139 moons just within our own solar system. Most of these are the property of the gas giant planets beyond Mars. More than just a nice accompaniment to planets, moons may have habitats in which liquid water could ebb and flow - and possibly be a suitable home for life. Planetary physicist Dr. Paul Estrada investigates how moons around gas giants are formed -- an important…
esiegel | September 24, 2010"Oh, you hate your job? Why didn't you say so? There's a support group for that. It's called EVERYBODY, and they meet at the bar." -Drew Carey
When you think of a galaxy, you probably think of a bright, dense core with huge, swirling outstretched spiral arms. Something, perhaps, like the Silverado Galaxy, below.
And while there are many galaxies like this, it isn't most of them! Oh, sure, most galaxies do have spiral arms, but they have something else, too. The Southern Pinwheel galaxy's got it,
the gorgeous NGC 1672's got it,
as does NGC 1300, which is directly face-on to us,
and some…
esiegel | September 23, 2010"But now it's gettin' late
And the moon is climbin' high.
I want to celebrate
See it shinin' in your eye." -Neil Young
The full Moon, beautiful as it is, isn't really all that rare!
Once every 29-30 days, the Moon returns to a completely full phase, where the entire "day side" of the Moon (the side lit up by the Sun) faces Earth.
In fact, our word "month" is named after the Moon, and -- unsurprisingly -- each of our 12 months has a special name for its full Moon. And traditionally, September's Moon, which typically (but not always) is the Moon closest to the Autumnal Equinox (for those of…
esiegel | September 22, 2010"Nothing travels faster than light, with the possible exception of bad news, which follows its own rules." -Douglas Adams
Every once in a while, a star in our own galaxy can do something to surprise us. Over in the constellation of the Unicorn lived a quiet, run-of-the-mill star named V838 Monocerotis. But in early 2002, it brightened incredibly rapidly, and the before-and-after pictures were rather astonishing.
What was initially thought to be a nova turned out to be much, much more fascinating by time the Hubble Space telescope got around to looking at it in May of 2002.
Warning: what you'…
esiegel | September 15, 2010"It doesn't matter what temperature the room is, it's always room temperature."
-Steven Wright
Far and away, one of the greatest things the Universe has ever created are dense clusters of galaxies!
The Coma Cluster, shown above, is a classic example of one of these colossal objects. (And as always, click on it for the huge version.) These giant clusters of galaxies contain over 1,000 galaxies that are Milky Way-sized or bigger, and span a few tens of millions of light years across space.
Compare that with our paltry local group of galaxies, where we have exactly two galaxies Milky Way-sized…
krandall | September 14, 2010By Dr. Mark R. Showalter
Planetary astronomer at the Carl Sagan Center for the Study of Life in the Universe, SETI Institute
It was just a few months ago that Stephen Hawking was making headlines with his bold assertion that extraterrestrial beings, if they exist, are best avoided. His argument was based in part upon the fact that the arrival of Christopher Columbus to the "New World" didn't work out so well for the Native Americans who were already here. However, upon closer inspection, Hawking's ideas fell apart. Even if nomadic tribes of ETs are really out there looking for a handy source…
drorzel | September 14, 2010Not long ago, a new preprint on the fine structure constant got a bunch of press, nicely summed up by the Knight Science Journalism Tracker last week. I meant to say something about this last week, but what with it being the first week of classes and all, I didn't find the time.
I still think it's worth writing about, though, so after a reproduction of the key figure, we'll have the usual Q&A-format explanation of why I don't quite trust this result:
So what's this all about? The preprint in question is the latest in a series of attempts to measure possible changes in the fine structure…
esiegel | September 13, 2010"I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use." -Galileo Galilei
While practically every scientist (and 79% of Americans) accept that the Earth and the other planets go around the Sun, it isn't quite everyone. In fact, a number of people have recently pointed out the following conference to me.
That's right, this November, a group of people are going to get together and try to put together as convincing an argument as possible for geocentrism, or the model that the Sun (and all the other planets)…
esiegel | September 10, 2010"Consideration of particle emission from black holes would seem to suggest that God not only plays dice, but also sometimes throws them where they cannot be seen." -Stephen Hawking
Last week, I wrote about how high-energy cosmic rays strike Earth's atmosphere and wind up bombarding everything on Earth's surface with super-fast moving particles, some of which are even unstable!
In passing, I mentioned that these cosmic rays (mostly protons) come from a variety of sources, such as the Sun, neutron stars, supernova remnants, the centers of galaxies, and (everyone's favorite) black holes.
(…
esiegel | September 3, 2010"We have been forced to admit for the first time in history not only the possibility but the fact of the growth and decay of the elements of matter. With radium and with uranium we do not see anything but the decay. And yet, somewhere, somehow, it is almost certain that these elements must be continuously forming. They are probably being put together now in the laboratory of the stars. ... Can we ever learn to control the process. Why not? Only research can tell." -Robert Millikan
Ah, energy, if only you were free, limitless, and easily accessible. If you were, we could do anything we wanted…
esiegel | September 1, 2010They will see us waving from such great heights
"Come down now," they'll say.
But everything looks perfect from far away
"Come down now," but we'll stay. -The Postal Service
It isn't the weekend, but I'd feel terrible showing you these pictures without giving you the right song to take you through it, so here's Iron & Wine's cover of a great song by The Postal Service:
Such Great Heights.Back in the early 1970s, the United States sent the first spacecraft, successfully, towards Mercury, the innermost planet of our Solar System. Before losing its functionality, Mariner 10 managed to…
drorzel | August 31, 2010Sunday was a really long day around Chateau Steelypips, and I couldn't see staying awake to watch the premiere of Phil Plait's Bad Universe on the Discovery Channel, so I'm way late in writing about it. I DVRed it, though, and watched it last night.
The theme of the premiere/ pilot was killer rocks from out of space, and focused on Phil getting his MythBusters on to test various ideas about asteroid or comet impacts and how to stop them. They blew up a scale model, shot projectiles into various types of rock to simulate nuclear bombs or kinetic impacts, all in the name of testing what would…